package ifdemo;

import java.util.Scanner;
public class IfElseDemo {
		public static void mian(String[] args) {
		Scanner scan = new Scanner(System.in);
		int a = scan.nextInt();
			if (a >= 90) {
				System.out.println("优");
		}else if(a>=70) {
			System.out.println("良");
			
		}else if(a>=60) {
			System.out.println("及格");
			
		}else {
			System.out.println("挂科");
			
		}
			
		}
	}


